Measurement and report for cross-link interference management based on reference signals

ABSTRACT

Systems and methods for reducing cross-link interference in a wireless system are disclosed. In some embodiments, a method of operation of a wireless device in a wireless system comprises receiving, from a serving Access Point (AP), wireless device specific Sounding Reference Signal (SRS) or Demodulation Reference Signal (DMRS) configuration information for one or more potential aggressor wireless devices. The method further comprises performing one or more measurements on at least one of the one or more potential aggressor wireless devices using the wireless device specific SRS or DMRS configuration information for the at least one of the one or more potential aggressor wireless devices and reporting at least one of the one or more measurements to the serving AP. In this manner, cross-link interference measurement and reporting is enabled.

RELATED APPLICATIONS

This application is a continuation of U.S. application Ser. No.16/638,158, filed Feb. 11, 2020, which is a 35 U.S.C. § 371 nationalphase filing of International Application No. PCT/SE2018/050808, filedAug. 10, 2018, which claims the benefit of provisional patentapplication Ser. No. 62/544,408, filed Aug. 11, 2017, the disclosures ofwhich are hereby incorporated herein by reference in their entireties.

BACKGROUND

New Radio (NR) design is based on a flexible structure where any timedomain resource for transmission can be allocated for downlink or uplinkor a combination of both. If the downlink and uplink transmissions occuron different carriers, it resembles the Frequency Division Duplexing(FDD) type of operation as in Long Term Evolution (LTE). However, ifthey occur on the same carrier it resembles the Time Division Duplexing(TDD) type of operation in LTE. Due to the built-in flexible design inNR, the NR operation is sometimes referred to as dynamic TDD operation.This enables NR to maximally utilize available radio resources in themost efficient way for both traffic directions. The traditional LTEtechnology only supports static TDD, where time domain resources aresplit between downlink and uplink based on a long term configuration, orflexible TDD operation where the changes in the downlink and uplinkconfiguration can be made only over a period of 5 milliseconds (ms). Incontrast, NR is based on the ability to flexibly choose the direction oftransmission in periods of 1 ms or less.

The term “Access Point (AP)” is used herein to indicate a node thatsupports communications to one or more User Equipment devices (UEs). AnAP is to be considered as generic terminology that represents any kindof node, e.g., a NR base station (gNB) in a Fifth Generation (5G) NRnetwork as being specified in Third Generation Partnership Project(3GPP). Although dynamic TDD brings significant performance gain at lowto medium loads, the performance benefits become smaller as the trafficload increases due to the cross-link interference. FIG. 1 illustratesthe cross-link interference issue in a NR dynamic TDD system. As shownin FIG. 1, if two cells have different traffic directions, UE1 indownlink experiences very strong interference from UE2 which can becloser than the serving AP1. From AP2 in uplink perspective, AP2 willalso experience interference from AP1 since AP1 is transmitting. Thiscross-link interference at high load is the key impediment toperformance gains from dynamic TDD operation at higher loads as comparedto static TDD. Most solutions to minimize the cross-link interferenceinvolve defining signaling between APs in order to exchange informationregarding the sources and the levels of interference. However, real-timesignaling usually requires overhead and complexity in equipment.Therefore, a more intelligent solution for cross-link interferencemanagement without inter-cell signaling is required.

In NR, there is a Sounding Reference Signal (SRS) transmitted from theUE. The main purpose of it is for estimating channel status in all orpart of carrier bandwidth in a different time granularity. In a TDDsystem, this SRS can be also used for reciprocity based channelestimation for downlink transmission. In NR, SRS can be UE specificallyconfigured by allocating a different time (e.g., slot, symbol),frequency (sub-band or comb number), reference signal sequence, orcyclic shift, as shown in FIG. 2. In particular, FIG. 2 illustrates anexample of frequency division multiplexing of multiple SRS transmissionsfrom different UEs for the four combs case (i.e., for Comb-4).

In NR, data transmissions by the UE carried by the Physical UplinkShared Channel (PUSCH) also contain a Demodulation Reference Signal(DMRS) that is used by the gNB to perform channel estimation in order todemodulate and decode the data. Unlike the SRS, the DMRSs are nottransmitted without the transmission of any associated datatransmissions.

SUMMARY

Systems and methods for reducing cross-link interference in a wirelesssystem are disclosed. In some embodiments, a method of operation of awireless device in a wireless system comprises receiving, from a servingAccess Point (AP), wireless device specific Sounding Reference Signal(SRS) or Demodulation Reference Signal (DMRS) configuration informationfor one or more potential aggressor wireless devices. The method furthercomprises performing one or more measurements on at least one of the oneor more potential aggressor wireless devices using the wireless devicespecific SRS or DMRS configuration information for the at least one ofthe one or more potential aggressor wireless devices and reporting atleast one of the one or more measurements to the serving AP. In thismanner, cross-link interference measurement and reporting is enabled.

In some embodiments, the wireless device is served by the serving AP ona serving cell of the wireless device and the one or more potentialaggressor wireless devices are served by at least one other cell, the atleast one other cell being different than the serving cell of thewireless device.

In some embodiments, the method further comprises receiving, from theserving AP, a request for periodic measurement reporting of SRS or DMRStransmitted by one or more aggressor wireless devices served by one ormore other APs. In some embodiments, reporting the at least one of theone or more measurements to the serving AP comprises reporting the atleast one of the one or more measurements to the serving AP inaccordance with the request. In some embodiments, the request isspecific for the wireless device. In some other embodiments, the requestis a broadcast request. In some embodiments, the request specifies areport period.

In some embodiments, the method further comprises receiving, from theserving AP, one or more triggering conditions for aperiodic measurementreporting of SRS or DMRS transmitted by one or more aggressor wirelessdevices served by one or more other APs. In some embodiments, the one ormore triggering conditions comprise: a triggering condition thatReference Signal Received Power (RSRP) from the serving cell of thewireless device is below a certain threshold; a triggering conditionthat an aggregate cross-link interference exceeds a certain threshold; atriggering condition that a ratio of the aggregate cross-linkinterference and overall aggregate interference exceeds a threshold;and/or a triggering condition that is based on an estimated value of aparameter that is related to a burstiness of the RSRP from the servingcell, the aggregate cross-link interference, and/or the ratio of theaggregate cross-link interference and the overall aggregateinterference. In some embodiments, reporting the at least one of the oneor more measurements to the serving AP comprises reporting the at leastone of the one or more measurements to the serving AP upon occurrence ofat least one of the one or more triggering conditions.

In some embodiments, reporting the at least one of the one or moremeasurements to the serving AP comprises reporting the at least one ofthe one or more measurements and corresponding aggressor wireless deviceinformation. In some embodiments, the corresponding aggressor wirelessdevice information comprises corresponding SRS or DMRS configurationinformation and/or corresponding resource allocation information.

In some embodiments, the one or more measurements comprise one or moreRSRP measurements or parts of one or more RSRP measurements.

In some embodiments, the at least one of the one or more measurementsreported to the AP comprise: a measurement for a potential aggressorwireless device for which a contribution of the potential aggressorwireless device to an overall cross-link interference is above a certainthreshold;

a measurement for a potential aggressor wireless device for which adifference between the contribution of the potential aggressor wirelessdevice to the overall cross-link interference and the overall cross-linkinterference is above a certain threshold; a measurement for a potentialaggressor wireless device for which a difference between thecontribution of the potential aggressor wireless device to the overallcross-link interference and an overall interference is above a certainthreshold; and/or a measurement for a potential aggressor wirelessdevice for which a difference between the contribution of the potentialaggressor wireless device to the overall cross-link interference and awanted signal strength is above a certain threshold.

In some embodiments, the wireless device specific SRS or DMRSconfiguration information comprises wireless device specifictime-frequency resource allocation and cell or wireless device specificSRS configuration information.

In some embodiments, the wireless device specific SRS or DMRSconfiguration information comprises information that indicatesOrthogonal Frequency Division Multiplexing (OFDM) symbols used for SRStransmission, Reference Signal (RS) sequences used, frequency hoppingconfiguration, sub-band index, comb configuration or number, powersetting, number of cyclic shifts, time periods where SRS transmissionsshould be measured, and/or a periodicity of measurement opportunities.

In some embodiments, the method further comprises receiving, from theserving AP, information that indicates one or more measurement occasionsfor performing measurements on the one or more potential aggressorwireless devices.

In some embodiments, performing the one or more measurements on the atleast one of the one or more potential aggressor wireless devicescomprises blindly attempting to detect a DMRS from a set of DMRSs forthe one or more potential aggressor wireless device.

Embodiments of a wireless device for a wireless system are alsodisclosed. In some embodiments, a wireless device for a wireless systemis adapted to receive, from a serving AP, wireless device specific SRSor DMRS configuration information for one or more potential aggressorwireless devices, perform one or more measurements on at least one ofthe one or more potential aggressor wireless devices using the wirelessdevice specific SRS or DMRS configuration information for the at leastone of the one or more potential aggressor wireless devices, and reportat least one of the one or more measurements to the serving AP.

In some embodiments, a wireless device for a wireless system comprisesone or more transceivers and circuitry associated with the one or moretransceivers whereby the wireless device is operable to receive, from aserving AP, wireless device specific SRS or DMRS configurationinformation for one or more potential aggressor wireless devices,perform one or more measurements on at least one of the one or morepotential aggressor wireless devices using the wireless device specificSRS or DMRS configuration information for the at least one of the one ormore potential aggressor wireless devices, and report at least one ofthe one or more measurements to the serving AP.

Embodiments of a method of operation of an AP in a wireless system arealso disclosed. In some embodiments, a method of operation of an AP in awireless system comprises sending, to a wireless device, wireless devicespecific SRS or DMRS configuration information for one or more potentialaggressor wireless devices and receiving, from the wireless device, ameasurement report comprising at least one measurement of at least oneof the one or more potential aggressor wireless devices.

In some embodiments, the wireless device is served by the AP on aserving cell of the wireless device and the one or more potentialaggressor wireless devices are served by at least one other cell, the atleast one other cell being different than the serving cell of thewireless device.

In some embodiments, the method further comprises sending, to thewireless device, a request for periodic measurement reporting of SRS orDMRS transmitted by one or more aggressor wireless devices served by oneor more other APs.

In some embodiments, the method further comprises sending, to thewireless device, one or more triggering conditions for aperiodicmeasurement reporting of SRS or DMRS transmitted by one or moreaggressor wireless devices served by one or more other APs.

In some embodiments, the wireless device specific SRS or DMRSconfiguration information comprises wireless device specifictime-frequency resource allocation and cell or wireless device specificSRS configuration information.

In some embodiments, the wireless device specific SRS or DMRSconfiguration information comprises information that indicates OFDMsymbols used for SRS transmission, RS sequences used, frequency hoppingconfiguration, sub-band index, comb configuration or number, powersetting, number of cyclic shifts, time periods (e.g., slots) where SRStransmissions should be measured, and/or a periodicity of themeasurement opportunities.

In some embodiments, the method further comprises receiving, from one ormore other APs, the wireless device specific SRS or DMRS configurationinformation for the one or more potential aggressor wireless devices.

Embodiments of an AP for a wireless system are also disclosed. In someembodiments, an AP for a wireless system is adapted to send, to awireless device, wireless device specific SRS or DMRS configurationinformation for one or more potential aggressor wireless devices andreceive, from the wireless device, a measurement report comprising atleast one measurement of at least one of the one or more potentialaggressor wireless devices.

In some embodiments, an AP for a wireless system comprises at least oneprocessor and memory comprising instructions executable by the at leastone processor whereby the AP is operable to send, to a wireless device,wireless device specific SRS or DMRS configuration information for oneor more potential aggressor wireless devices and receive, from thewireless device, a measurement report comprising at least onemeasurement of at least one of the one or more potential aggressorwireless devices.

In some embodiments, a method of operation of an AP in a wireless systemcomprises signaling, to one or more other APs, to indicate wirelessdevice specific transmission parameters which correspond to identifiedaggressor wireless devices based on SRS or DMRS measurement reportsreceived from a victim wireless device.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawing figures incorporated in and forming a part ofthis specification illustrate several aspects of the disclosure, andtogether with the description serve to explain the principles of thedisclosure.

FIG. 1 illustrates the cross-link interference issue in a New Radio (NR)dynamic Time Division Duplexing (TDD) system;

FIG. 2 illustrates an example of Frequency Domain Multiplexing (FDM)multiplexing of multiple Sounding Reference Signal (SRS) transmissionsfrom different User Equipment devices (UEs) (Comb-4 case);

FIG. 3 illustrates one example of a wireless system in which embodimentsof the present disclosure may be implemented;

FIG. 4 illustrates signaling for SRS based UE to UE interferencemeasurement and report in a NR dynamic TDD system (a SRS based example)according to some embodiments of the present disclosure;

FIG. 5 illustrates the operation of the system of FIG. 3 in accordancewith at least some embodiments of the present disclosure;

FIGS. 6 and 7 illustrate example embodiments of a wireless device; and

FIGS. 8 through 10 illustrate example embodiments of a network node.

DETAILED DESCRIPTION

The embodiments set forth below represent information to enable thoseskilled in the art to practice the embodiments and illustrate the bestmode of practicing the embodiments. Upon reading the followingdescription in light of the accompanying drawing figures, those skilledin the art will understand the concepts of the disclosure and willrecognize applications of these concepts not particularly addressedherein. It should be understood that these concepts and applicationsfall within the scope of the disclosure.

Radio Node: As used herein, a “radio node” is either a radio access nodeor a wireless device.

Radio Access Node or Access Point (AP): As used herein, a “radio accessnode” or “radio network node” or “AP” is any node in a radio accessnetwork of a cellular communications network that operates to wirelesslytransmit and/or receive signals. Some examples of a radio access nodeinclude, but are not limited to, a base station (e.g., a New Radio (NR)base station (gNB) in a Third Generation Partnership Project (3GPP)Fifth Generation (5G) NR network or an enhanced or evolved Node B (eNB)in a 3GPP Long Term Evolution (LTE) network), a high-power or macro basestation, a low-power base station (e.g., a micro base station, a picobase station, a home eNB, or the like), and a relay node.

Core Network Node: As used herein, a “core network node” is any type ofnode in a core network. Some examples of a core network node include,e.g., a Mobility Management Entity (MME), a Packet Data Network Gateway(P-GW), a Service Capability Exposure Function (SCEF), or the like.

Wireless Device: As used herein, a “wireless device” is any type ofdevice that has access to (i.e., is served by) a cellular communicationsnetwork by wirelessly transmitting and/or receiving signals to a radioaccess node(s). Some examples of a wireless device include, but are notlimited to, a User Equipment device (UE) in a 3GPP network and a MachineType Communication (MTC) device.

Network Node: As used herein, a “network node” is any node that iseither part of the radio access network or the core network of acellular communications network/system.

Note that the description given herein focuses on a 3GPP cellularcommunications system and, as such, 3GPP terminology or terminologysimilar to 3GPP terminology is oftentimes used. However, the conceptsdisclosed herein are not limited to a 3GPP system.

Note that, in the description herein, reference may be made to the term“cell;” however, particularly with respect to 5G NR concepts, beams maybe used instead of cells and, as such, it is important to note that theconcepts described herein are equally applicable to both cells andbeams.

The present disclosure proposes signaling and methods for measurementreports based on reference signals, e.g., Reference Signal ReceivedPower (RSRP) measurement and report from the UE to a serving gNB for thepurpose of cross-link interference management.

The following advantages have been identified. The solutions enable UEto UE cross-link interference measurement and reporting. The solutionsenable an individual gNB to monitor UE to UE cross-link interferencesituations to trigger proper cross-link interference management. Thesolutions reduce measurement complexity. The solutions are used tomitigate UE to UE cross-link interference and to improve systemperformance.

In the following, embodiments of the present disclosure are describedusing RSRP as an example of a measurement that is made based on a knownReference Signal (RS), e.g., the Sounding Reference Signal (SRS) or theDemodulation Reference Signal (DMRS). However, it should be apparent tothose skilled in the art that the teachings of the present disclosureare applicable to other such measurements as well. Furthermore, wedescribe different signaling and methods to estimate RSRP from one UEbased on SRS or DMRS and reporting the results to a serving gNB.

FIG. 3 illustrates one example of a wireless communication system 10 inwhich embodiments of the present disclosure may be implemented. In thisexample, the wireless communication system 10 is a cellularcommunications network and, in particular, is a 3GPP NR cellularcommunications network. As illustrated, the wireless communicationsystem 10 includes a number of wireless devices 12 (i.e., wirelesscommunication devices 12 or UEs 12). In addition, the wirelesscommunication system 10 includes a Radio Access Network (RAN) thatincludes a number of radio access nodes 14 (e.g., gNBs) (also referredto herein as APs 14) serving corresponding coverage areas or cells 16.The radio access nodes 14 are connected to a core network 18, whichincludes a number of core network nodes (not shown), as will beappreciated by one of skill in the art.

New signaling is disclosed to support SRS and/or DMRS based RSRPmeasurement from one UE 12 in a neighboring cell and to support thereporting of measurement results. In this regard, FIG. 4 illustrates anexample of signaling for SRS based UE to UE interference measurement andreporting in a NR dynamic Time Division Duplexing (TDD) system. As shownin FIG. 4, a victim UE 12-1 (i.e., the SRS measuring UE) measures one ormultiple SRS transmissions corresponding to one or multiple aggressorUEs 12-2 (i.e., SRS transmitting UEs) in order to estimate RSRP for eachaggressor UE 12-2. Note that for the example of FIG. 4 and the followingdiscussion, the radio access nodes 14 (i.e., the APs) are gNBs 14, i.e.,a first gNB 14-1 serving the victim UE 12-1 and a second gNB 14-2serving the aggressor UE 12-2. However, it should be understood thatthis discussion relates more generally to any type of radio access node.Further, while FIG. 4 illustrates an example that uses SRS, DMRS mayadditionally or alternatively be used.

For this, the following signaling is introduced:

-   -   Signaling from a serving gNB 14-1 to its UE 12-1 to request        periodic measurement reports of SRS or DMRS transmitted by        aggressor UEs 12-2 in other gNBs 14-2 (i.e., served by other        gNBs 14-2);    -   Signaling from a serving gNB 14-1 to its UE 12-1 to provide        measurement triggering condition related information for an        aperiodic measurement report of SRS or DMRS transmitted by        potential aggressor UEs 12-2 in other cells;    -   Signaling from a serving gNB 14-1 to its UE 12-1 to provide UE        specific SRS or DMRS configuration related information of        potential aggressor UEs 12-2 in other cells;    -   Signaling from a served UE 12-1 to a serving gNB 14-1 to report        SRS or DMRS measurement results related information for        interfering UEs 12-2;    -   Signaling between gNBs 14-1 and 14-2 to exchange UE specific SRS        or DMRS configurations; and/or    -   Signaling between gNBs 14-1 and 14-2 to indicate UE specific        transmission parameters which correspond to identified aggressor        UEs 12-2 based on SRS or DMRS measurement reports. This can be        via unspecified signaling means or over standard interfaces such        as the Xn interface.        It should be noted that the inter-gNB signaling and inter-UE/gNB        signaling are not necessarily dependent.

The signaling to the UE 12-1 may be delivered via higher layersignaling, physical layer signaling, or a combination thereof. Themeasurement configuration for SRS can allow for configuration ofperiodic measurements by the UE 12-1, whereas the measurementconfiguration for DMRS is not periodic since the occurrence of the DMRSis dependent on data scheduling and, in general, less predictable.Therefore, in one non-limiting example of the use of the DMRS in thepresent disclosure, measurements on the DMRS are made opportunisticallyby the UE 12-1 by blindly attempting to detect a DMRS from the set ofDMRSs.

The details of a SRS or DMRS measurement report request for a periodicreport and triggering conditions that a gNB 14-1 uses to send therequest are now described. The request can be UE specific or broadcastto enable reports from all associated UEs 12 in a serving gNB 14-1. Thesignal can be sent via higher layer (Radio Resource Control (RRC))signaling, physical layer signaling (Downlink Control Information (DCI)messages), or via a combination of higher layer and physical layer (DCImessages) signaling. In the latter option, the higher layer signalingmay provide a small set of triggering conditions from which the DCIsignaling can dynamically trigger a measurement report.

The request also specifies a report period. As a non-limiting example,there are several triggering conditions at a gNB side to send the UEspecific measurement request signal (i.e., used by the gNB 14-1 totrigger the sending of the UE specific measurement request), whichinclude any one or more of the following:

-   -   The estimated value of a parameter related to the received        interference, e.g., downlink Signal to Interference plus Noise        Ratio (SINR), is below a threshold (e.g., a predefined        threshold). This parameter can be derived from the feedback        provided by the UE 12-1 for link adaptation purposes.    -   The number of downlink retransmissions in a certain period of        time exceeds a threshold (e.g., a predefined threshold).    -   The number of consecutive retransmissions exceeds a threshold        (e.g., a predefined threshold).    -   The buffer size of the UE 12-1 for downlink exceeds a threshold        (e.g., a predefined threshold).    -   The estimated value of a parameter that is related to the        burstiness of any of the above measures, e.g., the variance or        the number of measurements that exceed the average by more than        a certain amount, exceeds a threshold (e.g., a predefined        threshold). Examples include:        -   The difference between the maximum and minimum measurements            of any of above mentioned values during a certain period of            time is larger than a certain threshold (e.g., a predefined            threshold); and        -   The difference between the maximum and average of            measurements of any of the above values during a certain            period of time is larger than a certain threshold (e.g., a            predefined threshold).    -   The number of UEs 12 fulfilling any one or more of the above        conditions exceeds a threshold (e.g., a predefined threshold).

If the number of UEs 12 that meets any one of above conditions exceeds athreshold (e.g., a predefined threshold), the request signal can bebroadcast to all associated UEs 12.

Triggering conditions for an aperiodic, event triggered SRS or DMRSmeasurement report will now be described. In some embodiments, thereport condition is predefined with a table and the index correspondingto each condition defined in a table can be signaled to UEs 12. Thesignaled conditions can include any one or more of the following:

-   -   RSRP or Reference Signal Received Quality (RSRQ) from a serving        cell is below a certain threshold (e.g., a predefined        threshold).    -   Aggregate cross-link interference exceeds a certain threshold.        The aggregate cross-link interference can be obtained by        measuring all indicated SRS resource elements of aggressor UEs        12-2.    -   Ratio of aggregate cross-link interference and overall aggregate        interference exceeds a threshold (e.g., a predefined threshold).    -   The estimated value of a parameter that is related to the        burstiness of any of the above measures, e.g., the variance or        the number of measurements that exceed the average by more than        a certain amount, exceeds a threshold (e.g., a predefined        threshold). Examples include:        -   The difference between the maximum and minimum measurements            of any of above mentioned values during a certain period of            time is larger than a certain threshold (e.g., a predefined            threshold); and        -   The difference between the maximum and average of            measurements of any of the above values during a certain            period of time is larger than a certain threshold (e.g., a            predefined threshold).

The information of SRS or DMRS configuration which is signaled to victimUEs (e.g., the UE 12-1, which is also referred to as a measuring UE) andused by the victim UEs to perform measurement on aggressor UEs will nowbe described. Both UE specific time-frequency resource allocation andcell- (or UE-) specific SRS configuration information are signaled. Asnon-limiting examples, the information can include any one orcombinations of the number of Orthogonal Frequency Division Multiplexing(OFDM) symbols used for SRS transmission, RS sequences, frequencyhopping configuration, sub-band index, comb configuration/number, powersetting, and number of cyclic shifts the slots where SRS transmissionsshould be measured as well as the periodicity of the measurementopportunities. The configuration for the DMRS may use a smaller set ofparameters than the SRS.

The signaling can be sent via higher layer (RRC) signaling, physicallayer signaling (DCI messages), or via a combination of higher layer andphysical layer (DCI messages) signaling. In the latter option, thehigher layer signaling may provide a small set of parameter choices fromwhich the DCI signaling can dynamically indicate a particularconfiguration. In this option, the measurement report from the UE 12-1may also use the smaller parameter set used for dynamic signaling tominimize the overhead of transmitting the report to the gNB 14-1. Forinstance, the UE 12-1 may use a small set of indices to indicate thedetected SRS sequence. The gNB 14-1 (or alternatively the gNB 14-2) thendetermines the particular UE 12-2 generating cross-link interference forwhich the measurement was made by combining this report with the knownconfiguration conveyed to the UE via RRC signaling.

As part of the measurement configuration, the gNB 14-1 may indicate tothe UE 12-1 any of the following options:

-   -   A single measurement occasion at a particular time and frequency        resource for which a measurement report must be returned.    -   A set of measurement occasions occurring at specific times and        in particular frequency resources. The measurement occasions may        or may not be periodic in time. The reporting may be periodic or        aperiodic based on some triggering conditions.    -   Unspecified measurement occasions with the UE 12-1 attempting to        detect interfering UEs 12-2 on its own. In one non-limiting        example, the UE 12-1 may perform such measurements only when        some of the interference conditions based on a simpler signal        strength measure exceed a certain threshold (e.g., a predefined        threshold). The reporting may be periodic or aperiodic based on        some triggering conditions.

The details of the reported information will now be described. Thevictim UE 12-1 will report either RSRP or corresponding index which thepredetermined interference range belongs to. Since at least in somescenarios the victim UE 12-1 will report multiple RSRPs for multipleaggressor UEs 12-2, the reported RSRP information will also includecorresponding aggressor UE information. The corresponding aggressor UEinformation can be SRS or DMRS configuration or resource allocationinformation such as cyclic shift or RS sequence, sub-band index. Inaddition, only part of measured RSRP can be reported. One example isthat the first N largest RSRPs and corresponding UE SRS configurationinformation are reported. Another non-limiting example is selecting theaggressor UE 12-2 for report such that:

-   -   its contribution to overall cross-link interference is above a        certain threshold (e.g., a predefined threshold);    -   the difference between its cross-link interference contribution        and overall cross-link interference is above a certain threshold        (e.g., a predefined threshold);    -   the difference between its cross-link interference contribution        and overall interference is above a certain threshold (e.g., a        predefined threshold); and    -   the difference between its cross-link interference contribution        and wanted signal strength is above a certain threshold (e.g., a        predefined threshold).

FIG. 5 illustrates the operation of the victim UE 12-1, the AP 14-1serving the victim UE 12-1, and the AP 14-2 serving the one or moreaggressor UEs 12-2 according to at least some of the embodimentsdisclosed herein. As illustrated, the AP 14-1 receives or otherwiseobtains UE specific SRS or DMRS configuration information from the AP14-2 for one or more potential aggressor UEs, as described above (step100). Depending on the particular embodiment or scenario, the serving AP14-1 sends a request to the victim UE 12-1 for a periodic measurementreport or sends triggering conditions for aperiodic reporting, asdescribed above (step 102). The serving AP 14-1 also sends the UEspecific SRS or DMRS configuration information obtained for the one ormore potential aggressor UEs to the victim UE 12-1, as described above(step 104). The victim UE 12-1 then performs measurements on at leastone of the one or more potential aggressor UEs using the UE specific SRSor DMRS configuration information for the potential aggressor UE(s) andin accordance with either the request for periodic reporting or thetriggering conditions for aperiodic reporting, as described above (step106). The victim UE 12-1 sends a measurement report to the serving AP14-1, as described above (step 108). The measurement report may includea measurement(s) for only one aggressor UE 12-2 or multiple aggressorUEs 12-2, depending on the particular embodiment and scenario. At leastin some embodiments, the serving AP 14-1 sends the SRS or DMRSconfiguration information for the identified aggressor UE(s) 12-2 to theAP 14-2, as described above (step 110).

In summary, the present disclosure teaches signaling and methods formeasurements based on reference signals such as the SRS and DMRS andreporting of these measurements in order to manage UE to UE interferencein a dynamic TDD system. As discussed above, some of the aspectsdiscussed herein are introducing new signaling for measurement requestor measurement triggering conditions and also considering NR SRS or DMRSspecific information.

FIG. 6 is a schematic block diagram of the wireless device 12, or UE 12,according to some embodiments of the present disclosure. As illustrated,the wireless device 12 includes circuitry 20 comprising one or moreprocessors 22 (e.g., Central Processing Units (CPUs), ApplicationSpecific Integrated Circuits (ASICs), Field Programmable Gate Arrays(FPGAs), Digital Signal Processors (DSPs), and/or the like) and memory24. The wireless device 12 also includes one or more transceivers 26each including one or more transmitters 28 and one or more receivers 30coupled to one or more antennas 32. In some embodiments, thefunctionality of the wireless device 12 described herein may beimplemented in hardware (e.g., via hardware within the circuitry 20and/or within the processor(s) 22) or be implemented in a combination ofhardware and software (e.g., fully or partially implemented in softwarethat is, e.g., stored in the memory 24 and executed by the processor(s)22).

In some embodiments, a computer program including instructions which,when executed by the at least one processor 22, causes the at least oneprocessor 22 to carry out at least some of the functionality of thewireless device 12 according to any of the embodiments described hereinis provided. In some embodiments, a carrier containing theaforementioned computer program product is provided. The carrier is oneof an electronic signal, an optical signal, a radio signal, or acomputer readable storage medium (e.g., a non-transitory computerreadable medium such as memory).

FIG. 7 is a schematic block diagram of the wireless device 12, or UE,according to some other embodiments of the present disclosure. Thewireless device 12 includes one or more modules 34, each of which isimplemented in software. The module(s) 34 provide the functionality ofthe wireless device 12 described herein (e.g., as described with respectto FIGS. 4 and 5).

FIG. 8 is a schematic block diagram of a network node 36 (e.g., a radioaccess node 14 such as, for example, an eNB or gNB or a core networknode) according to some embodiments of the present disclosure. Asillustrated, the network node 36 includes a control system 38 thatincludes circuitry comprising one or more processors 40 (e.g., CPUs,ASICs, DSPs, FPGAs, and/or the like) and memory 42. The control system38 also includes a network interface 44. In embodiments in which thenetwork node 36 is a radio access node 14, the network node 36 alsoincludes one or more radio units 46 that each include one or moretransmitters 48 and one or more receivers 50 coupled to one or moreantennas 52. In some embodiments, the functionality of the network node36 described above may be fully or partially implemented in softwarethat is, e.g., stored in the memory 42 and executed by the processor(s)40.

FIG. 9 is a schematic block diagram that illustrates a virtualizedembodiment of the network node 36 (e.g., the radio access node 14 or acore network node) according to some embodiments of the presentdisclosure. As used herein, a “virtualized” network node 36 is a networknode 36 in which at least a portion of the functionality of the networknode 36 is implemented as a virtual component (e.g., via a virtualmachine(s) executing on a physical processing node(s) in a network(s)).As illustrated, the network node 36 optionally includes the controlsystem 38, as described with respect to FIG. 8. In addition, if thenetwork node 36 is the radio access node 14, the network node 36 alsoincludes the one or more radio units 46, as described with respect toFIG. 8. The control system 38 (if present) is connected to one or moreprocessing nodes 54 coupled to or included as part of a network(s) 56via the network interface 44. Alternatively, if the control system 38 isnot present, the one or more radio units 46 (if present) are connectedto the one or more processing nodes 54 via a network interface(s).Alternatively, all of the functionality of the network node 36 describedherein may be implemented in the processing nodes 54. Each processingnode 54 includes one or more processors 58 (e.g., CPUs, ASICs, DSPs,FPGAs, and/or the like), memory 60, and a network interface 62.

In this example, functions 64 of the network node 36 (e.g., thefunctions of the network nodes described above with respect to, e.g.,FIGS. 4 and 5) described herein are implemented at the one or moreprocessing nodes 54 or distributed across the control system 38 (ifpresent) and the one or more processing nodes 54 in any desired manner.In some particular embodiments, some or all of the functions 64 of thenetwork node 36 described herein are implemented as virtual componentsexecuted by one or more virtual machines implemented in a virtualenvironment(s) hosted by the processing node(s) 54. As will beappreciated by one of ordinary skill in the art, additional signaling orcommunication between the processing node(s) 54 and the control system38 (if present) or alternatively the radio unit(s) 46 (if present) isused in order to carry out at least some of the desired functions.Notably, in some embodiments, the control system 38 may not be included,in which case the radio unit(s) 46 (if present) communicates directlywith the processing node(s) 54 via an appropriate network interface(s).

In some particular embodiments, higher layer functionality (e.g., layer3 and up and possibly some of layer 2 of the protocol stack) of thenetwork node 36 may be implemented at the processing node(s) 54 asvirtual components (i.e., implemented “in the cloud”) whereas lowerlayer functionality (e.g., layer 1 and possibly some of layer 2 of theprotocol stack) may be implemented in the radio unit(s) 46 and possiblythe control system 38.

In some embodiments, a computer program including instructions which,when executed by the at least one processor 40, 58, causes the at leastone processor 40, 58 to carry out the functionality of the network node36 or a processing node 54 according to any of the embodiments describedherein is provided. In some embodiments, a carrier containing theaforementioned computer program product is provided. The carrier is oneof an electronic signal, an optical signal, a radio signal, or acomputer readable storage medium (e.g., a non-transitory computerreadable medium such as the memory 42, 60).

FIG. 10 is a schematic block diagram of the network node 36 according tosome other embodiments of the present disclosure. The network node 36includes one or more modules 66, each of which is implemented insoftware. The module(s) 66 provide the functionality of the network node36 described herein (e.g., the functionality of a corresponding one ofthe network nodes described in relation to, e.g., FIGS. 4 and 5).

While not being limited thereto, some example embodiments of the presentdisclosure are provided below.

Embodiment 1: A method of operation of a wireless device (12, 12-1) in awireless system (10), comprising: receiving (104), from a serving AP(14, 14-1), wireless device specific SRS or DMRS configurationinformation for one or more potential aggressor wireless devices (12,12-2); performing (106) one or more measurements on at least one of theone or more potential aggressor wireless devices (12, 12-2) using thewireless device specific SRS or DMRS configuration information for theat least one of the one or more potential aggressor wireless devices(12, 12-2); and reporting (108) at least one of the one or moremeasurements to the serving AP (14, 14-1).

Embodiment 2: The method of embodiment 1 further comprising receiving(102), from the serving AP (14, 14-1), a request for periodicmeasurement reporting of SRS or DMRS transmitted by one or moreaggressor wireless devices (12, 12-2) served by one or more other APs(14, 14-2).

Embodiment 3: The method of embodiment 1 further comprising receiving(102), from the serving AP (14, 14-1), one or more triggering conditionsfor aperiodic measurement reporting of SRS or DMRS transmitted by one ormore aggressor wireless devices (12, 12-2) served by one or more otherAPs (14, 14-2).

Embodiment 4: The method of any one of embodiments 1 to 3 wherein thewireless device specific SRS or DMRS configuration information compriseswireless device specific time-frequency resource allocation and cell orwireless device specific SRS configuration information.

Embodiment 5: The method of any one of embodiments 1 to 3 wherein thewireless device specific SRS or DMRS configuration information comprisesinformation that indicates OFDM symbols used for SRS transmission, RSsequences used, frequency hopping configuration, sub-band index, combconfiguration or number, power setting, number of cyclic shifts, timeperiods (e.g., slots) where SRS transmissions should be measured, and/ora periodicity of the measurement opportunities.

Embodiment 6: A wireless device (12) for a wireless system (10), thewireless device (12) adapted to perform the method of any one ofembodiments 1 to 5.

Embodiment 7: A wireless device (12) for a wireless system (10),comprising: one or more transceivers (26); and circuitry (20) associatedwith the one or more transceivers (26) whereby the wireless device (12)is operable to perform the method of any one of embodiments 1 to 5.

Embodiment 8: A wireless device (12) for a wireless system (10),comprising: one or more modules (34) operable to perform the method ofany one of embodiments 1 to 5.

Embodiment 9: A method of operation of an AP (14, 14-1) in a wirelesssystem (10), comprising: sending (104), to a victim wireless device (12,12-1), wireless device specific SRS or DMRS configuration informationfor one or more potential aggressor wireless devices (12, 12-2); andreceiving (108), from the victim wireless device (12, 12-1), ameasurement report comprising at least one measurement of at least oneof the one or more potential aggressor wireless devices (12, 12-2).

Embodiment 10: The method of embodiment 9 further comprising sending(102), to the victim wireless device (12, 12-1), a request for periodicmeasurement reporting of SRS or DMRS transmitted by one or moreaggressor wireless devices (12, 12-2) served by one or more other APs(14, 14-2).

Embodiment 11: The method of embodiment 9 further comprising sending(102), to the victim wireless device (12, 12-1), one or more triggeringconditions for aperiodic measurement reporting of SRS or DMRStransmitted by one or more aggressor wireless devices (12, 12-2) servedby one or more other APs (14, 14-2).

Embodiment 12: The method of any one of embodiments 9 to 11 wherein thewireless device specific SRS or DMRS configuration information compriseswireless device specific time-frequency resource allocation and cell orwireless device specific SRS configuration information.

Embodiment 13: The method of any one of embodiments 9 to 11 wherein thewireless device specific SRS or DMRS configuration information comprisesinformation that indicates OFDM symbols used for SRS transmission, RSsequences used, frequency hopping configuration, sub-band index, combconfiguration or number, power setting, number of cyclic shifts, timeperiods (e.g., slots) where SRS transmissions should be measured, and/ora periodicity of the measurement opportunities.

Embodiment 14: The method of any one of embodiments 9 to 11 furthercomprising receiving (100), from one or more other APs (14, 14-2), thewireless device specific SRS or DMRS configuration information for theone or more potential aggressor wireless devices (12, 12-2).

Embodiment 15: An AP (14, 14-1) for a wireless system (10), the AP (14,14-1) adapted to perform the method of any one of embodiments 9 to 14.

Embodiment 16: An AP (14, 14-1) for a wireless system (10), comprising:at least one processor (40, 58); and memory (42, 60) comprisinginstructions executable by the at least one processor (40, 58) wherebythe AP (14, 14-1) is operable to perform the method of any one ofembodiments 9 to 14.

Embodiment 17: An AP (14, 14-1) for a wireless system (10), comprising:one or more modules (66) operable to perform the method of any one ofembodiments 9 to 14.

Embodiment 18: A method of operation of an AP (14, 14-1) in a wirelesssystem (10), comprising: signaling (110), to one or more other APs (14,14-2), to indicate wireless device specific transmission parameterswhich correspond to identified aggressor wireless devices (12, 12-2)based on SRS or DMRS measurement reports received from a victim wirelessdevice (12, 12-2).

The following acronyms are used throughout this disclosure.

-   -   3GPP Third Generation Partnership Project    -   5G Fifth Generation    -   AP Access Point    -   ASIC Application Specific Integrated Circuit    -   CPU Central Processing Unit    -   DCI Downlink Control Information    -   DMRS Demodulation Reference Signal    -   DSP Digital Signal Processor    -   eNB Enhanced or Evolved Node B    -   FDD Frequency Division Duplexing    -   FDM Frequency Domain Multiplexing    -   FPGA Field Programmable Gate Array    -   gNB New Radio Base Station    -   LTE Long Term Evolution    -   MME Mobility Management Entity    -   ms Millisecond    -   MTC Machine Type Communication    -   NR New Radio    -   OFDM Orthogonal Frequency Division Multiplexing    -   P-GW Packet Data Network Gateway    -   PUSCH Physical Uplink Shared Channel    -   RAN Radio Access Network    -   RRC Radio Resource Control    -   RS Reference Signal    -   RSRP Reference Signal Received Power    -   RSRQ Reference Signal Received Quality    -   SCEF Service Capability Exposure Function    -   SINR Signal to Interference plus Noise Ratio    -   SRS Sounding Reference Signal    -   TDD Time Division Duplexing    -   UE User Equipment

Those skilled in the art will recognize improvements and modificationsto the embodiments of the present disclosure. All such improvements andmodifications are considered within the scope of the concepts disclosedherein.

What is claimed is:
 1. A method of operation of a wireless device in awireless system, the method comprising: receiving, from an Access Point(AP) serving the wireless device, Sounding Reference Signal (SRS)configuration information for cross-link interference (CLI) measurementsassociated with one or more potential aggressor wireless devices;receiving, from the AP serving the wireless device, a triggeringcondition for aperiodic CLI measurement reporting using the SRSconfiguration information; performing one or more CLI measurements usingthe SRS configuration information; and reporting at least one of the oneor more CLI measurements to the AP serving the wireless device.
 2. Themethod of claim 1, wherein the wireless device is served by the AP on aserving cell of the wireless device, wherein the one or more potentialaggressor wireless devices are served by at least one other cell, andwherein the at least one other cell is different than the serving cellof the wireless device.
 3. The method of claim 1, wherein the one ormore potential aggressor wireless devices are served by one or moreother APs.
 4. The method of claim 1, wherein the SRS configurationinformation is wireless device specific SRS configuration information.5. The method of claim 1, wherein the reporting of the at least one ofthe one or more CLI measurements to the AP serving the wireless deviceis performed upon occurrence of the triggering condition.
 6. A wirelessdevice for a wireless system, the wireless device comprising: one ormore transceivers; and circuitry associated with the one or moretransceivers whereby the wireless device is operable to: receive, froman Access Point (AP) serving the wireless device, Sounding ReferenceSignal (SRS) configuration information for cross-link interference (CLI)measurements associated with one or more potential aggressor wirelessdevices; receive, from the AP serving the wireless device, a triggeringcondition for aperiodic CLI measurement reporting using the SRSconfiguration information; perform one or more CLI measurements usingthe SRS configuration information; and report at least one of the one ormore CLI measurements to the AP serving the wireless device.
 7. Thewireless device of claim 6, wherein the wireless device is served by theAP on a serving cell of the wireless device, wherein the one or morepotential aggressor wireless devices are served by at least one othercell, and wherein the at least one other cell is different than theserving cell of the wireless device.
 8. The wireless device of claim 6,wherein the one or more potential aggressor wireless devices are servedby one or more other APs.
 9. The wireless device of claim 6, wherein theSRS configuration information is wireless device specific SRSconfiguration information.
 10. The wireless device of claim 6, whereinthe reporting of the at least one of the one or more CLI measurements tothe AP serving the wireless device is performed upon occurrence of thetriggering condition.
 11. A method of operation of an Access Point (AP)in a wireless system, the method comprising: sending, to a wirelessdevice, Sounding Reference Signal (SRS) configuration information forcross-link interference (CLI) measurements associated with one or morepotential aggressor wireless devices; sending, to the wireless device, atriggering condition for aperiodic CLI measurement reporting using theSRS configuration information; and receiving, from the wireless device,a measurement report comprising at least one CLI measurement obtainedusing the SRS configuration information.
 12. The method of claim 11,wherein the wireless device is served by the AP on a serving cell of thewireless device, wherein the one or more potential aggressor wirelessdevices are served by at least one other cell, and wherein the at leastone other cell is different than the serving cell of the wirelessdevice.
 13. The method of claim 11, wherein the one or more potentialaggressor wireless devices are served by one or more other APs.
 14. Themethod of claim 11, wherein the SRS configuration information iswireless device specific SRS configuration information.
 15. The methodof claim 11, wherein the reporting of the at least one CLI measurementsis performed upon occurrence of the triggering condition.
 16. An AccessPoint (AP) for a wireless system, the AP comprising: at least oneprocessor; and memory comprising instructions executable by the at leastone processor whereby the AP is operable to: send, to a wireless device,Sounding Reference Signal (SRS) configuration information for cross-linkinterference (CLI) measurements associated with one or more potentialaggressor wireless devices; send, to the wireless device, a triggeringcondition for aperiodic CLI measurement reporting using the SRSconfiguration information; and receive, from the wireless device, ameasurement report comprising at least one CLI measurement obtainedusing the SRS configuration information.
 17. The AP of claim 16, whereinthe wireless device is served by the AP on a serving cell of thewireless device, wherein the one or more potential aggressor wirelessdevices are served by at least one other cell, and wherein the at leastone other cell is different than the serving cell of the wirelessdevice.
 18. The AP of claim 17, wherein the one or more potentialaggressor wireless devices are served by one or more other APs.
 19. TheAP of claim 18, wherein the SRS configuration information is wirelessdevice specific SRS configuration information.
 20. The AP of claim 19,wherein the reporting of the at least one CLI measurements is performedupon occurrence of the triggering condition.